1. Field of the Invention
This invention generally relates to semiconductor memory devices, and, in particular, to regulating voltages in a memory, such as flash memory.
2. Description of the Related Art
Advancements in the memory technology have resulted in improved memories at a lower price. For example, flash memories today stole a greater number of bits per area at an overall lower cost-per-megabyte. The affordable price of flash memory has made it a popular choice among many application developers.
Flash memory (sometimes called xe2x80x9cflash RAMxe2x80x9d) is a type of non-volatile memory that can be erased and reprogrammed in units of memory called blocks. Flash memory is a variation of electrically erasable programmable read-only memory (EEPROM) that, unlike flash memory, is erased and rewritten at the byte level, which is slower than flash memory updating. Flash memory is commonly used to hold control code such as the basic input/output system (BIOS) in a personal computer. When BIOS needs to be changed (rewritten), the flash memory can be written in block (rather than byte) sizes, making it faster to update. Applications employing flash memory include digital cellular phones, digital cameras, LAN switches, computers, digital set-up boxes, embedded controllers, and other devices.
Flash memories generally use factory programmed trim bits (sometimes also referred to as xe2x80x9coption bitsxe2x80x9d) to configure the operation of the memory. The trim bits may be utilized to configure a variety of different settings in the memory, including voltage regulation levels and other marketing options. It may be desirable to regulate voltage levels in the memory during power up, for example, using voltage regulators, such as capacitor-divider voltage regulators. Furthermore, it may be desirable to have the new voltage take affect soon after the trim bits provide the new regulation voltage level. However, because selected voltage regulators, such as capacitor-divider voltage regulators, generally cannot change their voltage regulation value without a proper refresh of the capacitors, the new regulation value may not take effect as quickly as desired, thereby causing the regulators to operate unregulated.
In one aspect of the instant invention, a method is provided for regulating voltages in semiconductor devices. The method comprises providing a first voltage level using a voltage regulator, determining that a second voltage level is desired and initializing the voltage regulator to provide the second voltage level based on determining that the second voltage level is desired.
In another aspect of the instant invention, an apparatus is provided for regulating voltages in semiconductor devices. The apparatus comprises at least one storage cell, a refresh circuit, and a voltage regulator. The at least one storage cell is adapted to provide a voltage regulation value in response to receiving a control signal. The refresh circuit is adapted to provide a refresh signal based on receiving the control signal and a voltage regulator is communicatively coupled to the storage cell and the refresh circuit. The voltage regulator is adapted to provide a signal of a voltage level that is indicated by the voltage regulation value based on receiving the refresh signal.
In yet another aspect of the instant invention, a system is provided for regulating voltages in semiconductor devices. The system comprises a device and a memory. The memory is accessible by the device. The memory comprises a refresh circuit and a capacitor-divider voltage regulator. The refresh circuit is adapted to provide a refresh signal in response to determining that a change in a voltage level is desired. The capacitor-divider voltage regulator is adapted to provide a signal of a voltage level that is indicated by the voltage regulation value based on receiving the refresh signal.